Phenom is the latest CPU series from AMD, based on their new K10 architecture. In this short tutorial we will list the main specs of all Phenom models released or announced so far.

For a complete explanation about the new K10 architecture, please read our Inside AMD K10 Architecture tutorial.

The main differences between Phenom and Athlon 64 are the following:

• Use of a shared L3 memory cache.
• Use of HyperTransport 3.0 bus between the CPU and the chipset, increasing the available bandwidth between the CPU and the external world. It is important to notice that so far Phenom CPUs do not work at the maximum speed provided by HT3.
• Use of a separated voltage source for the CPU and for the embedded memory controller (a.k.a. “split plane” or “Dual Dynamic Power Management”, DDPM).
• Use of a separated clock generator for the memory controller, with a fixed value. This solves the problem that happens with Athlon 64 where depending on the CPU the memories don’t work at their full speed.
• Support for DDR2 memories up to DDR2-1066/PC2-8500 (Athlon 64 CPUs support up to DDR2-800/PC2-6400) on socket AM2+ models; support for DDR3 memories on socket AM3 models. Socket AM3 models can be installed on certified socket AM2+ motherboards, allowing them to work with DDR2 memories.

There are more differences between Phenom and Athlon 64 CPUs, as you can learn by reading the above mentioned tutorial.

Phenom CPUs can be installed on older socket AM2 motherboards, however they will be limited to the HyperTransport 2 transfer rate of 4,000 MB/s, won’t have the DDPM technology available and the memory controller will work at a lower clock rate (1.6 GHz).

Some Phenom II models are designed for socket AM3. They will work with DDR3 memory modules when installed on socket AM3 motherboards, and with DDR2 memory modules when installed on certified socket AM2+ motherboards.

So far AMD released or announced Phenom CPUs with three or four processing cores and Phenom II CPUs with two, three or four cores, with the following basic specs for all models:

• L1 memory cache of 128 KB per core;
• L2 memory cache of 512 KB per core;
• One L3 memory cache of 2 MB (4 MB or 6 MB on Phenom II) shared by all cores;
• HyperTransport bus working at 1.6 GHz (6,400 MB/s), 1.8 GHz (7,200 MB/s) or 2 GHz (8,000 MB/s), depending on the model. Please notice that HT3 provides two higher speed grades (2.4 GHz/9,600 MB/s and 2.6 GHz/10,400 MB/s) which aren’t being used yet.
• Socket AM2+ or AM3 (some Phenom II models)
• 65 nm manufacturing process (45 nm process on Phenom II)
• SSE4a instruction set, which is simply the addition of two new SSE instructions and despite its name it has nothing to do with SSE4.1 used on some Intel CPU's and that brings 47 new instructions.
• "Black Edition" models have their clock multiplier unlocked, meaning a higher overclocking capability, as you can configure then as if they were a CPU with a higher clock rate.